Question

A has a circumference of 10 inches. Find its approximate radius, diameter and area

Answer 1

• r = 5/π in

,

• D = 10/π in

,

• A = 25/π in²

Step-by-step explanation

The circumference of a circle is:

`C=2\pi r`

So if we know that the circumference is 10 inches we can find the radius:

`\begin{gathered} 10=2\pi\cdot r \\ r=(10)/(2\pi)=(5)/(\pi) \end{gathered}`

The diameter is twice the radius:

`D=2r=2\cdot(5)/(\pi)=(10)/(\pi)in`

And the area of a circle is:

`A=\pi r^2=\pi\cdot((5)/(\pi))^2=\pi\cdot(25)/(\pi^2)=(25)/(\pi)in^2`